endophasia

[ en-doh-fey-zhuh, -zhee-uh, -zee-ey ]
/ ˌɛn doʊˈfeɪ ʒə, -ʒi ə, -zi eɪ /

noun

internal speech with no audible vocalization.
Compare exophasia.

Origin of endophasia

< Italian endofasia. See endo-, -phasia